Hydrogen has attracted attention as an energy source having a low environmental load because only water is discharged when energy is extracted by its combustion. Therefore, in recent years, a method of producing hydrogen using methane as a raw material has attracted attention. Methane can be obtained from a biomass gas as next-generation energy independent of a fossil fuel.
Decomposition of methane requires a very large amount of energy, and hence a metal catalyst such as nickel or iron is mainly used for a thermal decomposition reaction of methane. However, in the thermal decomposition reaction of methane using the metal catalyst, precipitation of carbon on the metal catalyst occurs with production of hydrogen, resulting in deactivating the metal catalyst.
Therefore, hitherto, there has been proposed production of hydrogen using a carbon catalyst (for example, Patent Literature 1, Patent Literature 2, and Non Patent Literature 1). The carbon catalyst itself is a carbon material, and hence is hardly deactivated even when precipitation of carbon due to decomposition of methane occurs.